As a means for manufacturing an optical film such as light guide plate, light diffusion plate or lens, there is conventionally known a method to transfer a fine projections and depressions pattern to the surface of a film. For example, there has been proposed a system, which intermittently forms a fine projections and depressions pattern on a lengthy film wound in a roll shape, and a method thereof (Japanese Patent Application Kokai Publication No. 2005-199455 and Japanese Patent Application Kokai Publication No. 2005-310286).
In the above system and method, a film is supplied from a feed-out roll into a press unit, where the film is pressed onto a mold having a fine projections and depressions pattern and the pattern is transferred to form the projections and depressions pattern on the surface of the film. Before the film is pressed onto the mold to transfer the pattern, the mold is heated up to a temperature of a glass transit point of the film or higher. After completing the transfer, the mold is cooled down under a constant condition while keeping the press. When the mold is cooled down to the glass transit point of the film or lower, the pressure of the press is released and a certain tension is applied to the film thereby the film is released from the mold. However, this mold releasing method has a problem such that, depending on the characteristics of an applied resin or due to the wear of releasing agent applied on the mold surface, the film adheres to the mold and is hardly released therefrom. Also, there is another problem such that, when the film is forcibly pealed off from the mold, the mold surface may be damaged or stripping traces like scratches may be left on the surface of the film transferred with the pattern.
Also, there has been proposed another method in which a mold is previously formed with a warp, and at the same time when the pressure is released from the mold, a film formed with a pattern is automatically released due to its own elastic force (Japanese Patent Application Kokai Publication No. 2004-288845).
However, the above method has a problem such that, depending on its elastic characteristics, applicable molded article is limited. For example, in a case of a resin film of 0.3 mm or less in thickness, the method is not applicable thereto because the sufficient elastic force cannot be obtained.
On the other hand, although it is not a film forming system, there has been proposed a device for peeling off a film formed with a circuit pattern from a bonded backing plate as a device for peeling off a film adhered on a substrate surface (Japanese Patent Application Kokai Publication No. 2006-32400).
However, this above device is arranged so that a peeling member having a circular shape for holding the film at the end portion is rotated along a circular arc on the bonding surface to thereby release the film. However, since the device has a structure to hold the edge portion of film, the structure is not applicable to a continuous film wound in a roll shape. Also, the device is not applicable to a molding device such as a press because it is difficult to position the peeling member having a circular arc shape in a press-forming area.
Also, although it is not a film forming system, as a device for peeling off a stuck film, there has been proposed a device which peels off a film along a roll by rotating a roll on a sticking surface while holding film end portion (Japanese Patent Application Kokai Publication No. 2002-104726).
However, since the system proposed in Japanese Patent Application Kokai Publication No. 2002-104726 has a restriction such that the edge portion of the film has to be held same as the system proposed in Japanese Patent Application Kokai Publication No. 2006-32400, it cannot be applied to a continuous film having a roll shape.